For example, there is a configuration described in Japanese Patent No. 4737268 as a technology of interest for the disclosure. Japanese Patent No. 4737268 describes the following pulse transformer as a coil component.
The pulse transformer described in Japanese Patent No. 4737268 includes a drum-shaped core having a winding core portion and first and second flange portions provided at respective end portions of this winding core portion. Each of the first and second flange portions has an inner end surface that faces the side of the winding core portion and positions the corresponding end portion of the winding core portion, an outer end surface that faces the outer side opposite to the inner end surface, a bottom surface that couples the inner end surface with the outer end surface and faces the side of a mount substrate at mounting, and a top surface opposite to the bottom surface.
For example, four wires are wound around the winding core portion of the drum-shaped core. Three terminal electrodes are provided at each of the first and second flange portions. The terminal electrodes are positioned on the bottom surface of each flange portion. End portions of two wires are connected with two terminal electrodes among the three terminal electrodes on each flange portion. End portions of the residual two wires are commonly connected with the residual one terminal electrode.
Also, a plate-shaped core is bridged between the first and second flange portions. One principal surface of the plate-shaped core is in contact with the top surface of each of the first and second flange portions.
Such a pulse transformer is used for transmitting a communication signal and obtaining electrical insulation.